The present invention pertains to a method and a device for uniform coating of cylindrically shaped substrates with coating material that is deposited from a material cloud of material onto the substrates, wherein the substrates to be coated are brought into the environment of the material cloud.
Coating methods of this general class are known, for instance, for the application of optically active layers onto optical elements. In these methods, the substrate to be coated is positioned inside a vacuum-coating chamber in front of a coating source. The material that forms the layer is emitted from the coating source as a material cloud is deposited on the surfaces of the substrate facing the coating source. In order, for instance, to coat the aforementioned optical glasses on both sides, it is necessary to interrupt the coating process, turn the substrates 180.degree. and then continue the coating process. In the customary methods, the coating process of multi-surface substrates takes place successively for each substrate surface, the coating chambers having to be reopened each time to reposition the substrates in front of the coating sources. For this purpose the coating chambers must be ventilated or again evacuated for the performance of the subsequent coating process, which makes the known methods time-consuming and cost-intensive, particularly for coating a large series of identical substrates.
It is therefore an object of the invention to provide a method of the type described above in which the coating of a large series of substrates having a multi-planar surface is made possible without the need for interruption of the coating process for the purpose of repositioning the substrate surfaces to be coated.
It is a further object of the present invention to provide a device for coating substrates, by means of which the method of the invention can be implemented.